One of the processing challenges for producing reformulated gasoline is endpoint reduction. Lowering gasoline endpointo,as been reported to reduce pollution. A specification of 90% of the gasoline boils below 300.degree. F. has been proposed for California.
Zeolite beta has been found particularly well-suited for use in a catalyst for hydrocracking naphtha under mild conditions. U.S. Pat. No. 3,923,641 to Morrison, discloses that C.sub.5 + naphtha can be readily upgraded to a product which contains increased amounts of isobutane relative to n-butane, by hydrocracking the naphtha over zeolite beta. There is no disclosure of endpoint reduction in gasolines.
It has now been found that a C.sub.5 + naphtha, e.g., C.sub.6 + or C.sub.7 + naphtha can be hydrocracked by a process which comprises contacting the naphtha with a catalyst composition comprising a hydrogenation/dehydrogenation component and an acidic solid component comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal.
In the present invention a catalyst composition comprising a hydrogenation/dehydrogenation component and an acidic solid component comprising a Group IVB metal oxide modified with an oxyanion of a Group VIB metal is found to be selective for naphtha hydrocracking to reduce the endpoint of reformulated gasolines. The endpoint is lowered through selective hydrocracking of the C.sub.10 + fraction.